The present invention relates to an electronic stringed instrument and, more particularly, to an electronic stringed instrument which can be played by operations such as plucking, strumming, and the like, similar to those of a standard stringed instrument.
Electronic stringed instruments of this type as described in U.S. Pat. Nos. 4,336,734 and 4,658,690 are conventionally known. In the former electronic stringed instrument, a large number of touch-sensitive capacitive sensors for designating pitches of musical tones to be generated are embedded in a fingerboard formed on an instrument main body, and six strum bars capable of a plucking or strumming operation are stretched along a body formed on the instrument main body. In addition, string trigger switches each for initiating musical tone generation at a predetermined pitch designated by the corresponding sensor in cooperation with a corresponding strum bar are arranged at positions corresponding to the strum bars.
In this conventional electronic stringed instrument, a musical tone at a predetermined pitch designated by the sensor is produced as follows. The predetermined strum bar at a non-deviation position is depressed by a finger tip to be deviated toward a conductive member fixed to a bar support base side. When the strum bar is in electrical contact with the conductive member, the musical tone is produced. Therefore, when a player plays this electronic stringed instrument like a guitar play in practice, he experiences quite a different response from when he plays an acoustic stringed instrument (standard stringed instrument). More specifically, with the above stringed instrument, when the strum bar is depressed to be deviated and is in contact with the conductive member fixed to the bar support base, the desired musical tone begins to be produced. Therefore, in this electronic stringed instrument, a predetermined musical tone is not produced when the strum bar which has been deviated by a finger tip to a predetermined position is released. Thus, the player may often experience a slow response.
Traditional standard stringed instruments such as a koto in the East, or a harp, a guitar, and the like in the West have a mechanism in which surrounding air is vibrated by a vibration of a string to produce a predetermined musical tone. Upon analysis of a plucking operation of such a mechanism, it is found that the plucking operation comprises the first step wherein a string is deviated from its rest position (non-deviation state) to a predetermined position against its tension (in this step, the string merely accumulates predetermined energy to prepare for initiating vibration), and the second step wherein the string is released from the state (tense string state) wherein the string is deviated to the predetermined position. The string is vibrated mainly in the second step (string release step), thereby initiating production of a predetermined musical tone.
Therefore, when a standard stringed instrument is to be perfectly simulted by an electronic stringed instrument, it is important to simulate its playing operation, i.e., a tone generation start timing.
However, the tone generation start timing of the conventional electronic stringed instrument is considerably different from that of the traditional standard stringed instrument. For this reason, in order to obtain the same tone generation start timing as that of the standard stringed instrument, a high playing skill is required.
On the other hand, in the latter conventional electronic stringed instrument, six conductive strings supplied with a current and a pitch designating section consisting of a large number of touch sensors for sensing depressed string positions when the strings are depressed are arranged on a fingerboard formed on an instrument main body. In addition, trigger strings corresponding in number to the conductive strings and a string trigger detecting section for detecting vibration of these trigger strings are arranged on a body formed on the instrument main body.
However, in this conventional electronic stringed instrument, the string trigger detection section is constituted by a magnet arranged at the end portion of each trigger string, a housing for slidably storing the magnet, and a Hall effect sensor for detecting an axial movement of the magnet in the housing. In addition, an electronic control device is arranged. The control device outputs a tone trigger signal only when the trigger string is released from a tense state. The control device does not output a tone trigger signal while the trigger string is deviated from the non-deviation position to the predetermined position and, as a result, while the Hall effect sensor is axially moved in the housing. Therefore, the entire instrument becomes complicated. Since the string trigger detecting section is constituted by the Hall effect sensors, the instrument becomes expensive accordingly. In addition, since the Hall effect characteristics are easily changed over time, it is difficult to obtain a stable tone trigger signal over a long period of time.